The present invention relates to an egg tray of the kind set forth in the preamble of claim 1.
Egg trays of the kind referred to above normally comprise thirty pockets arranged in five rows of six pockets each. They are normally used by the egg producers for packaging eggs to be delivered to e.g. a wholesale distribution site comprising a packaging station. The egg producers fill the egg trays manually or by using suitable machinery, while at the packaging station, the eggs are removed mechanically in machines normally using arrays of suction cups, in the example referred to arranged in five rows of six cups each, for transferring the eggs from the egg trays supplied by the producer to a quality and grading control stage and from there to a final packaging stage, in which the eggs are placed in e.g. smaller egg cartons suitable for sale in retail shops.
In previously known egg trays of the kind referred to initially, the egg-supporting surface consists of a number of abutment regions on the sides of the posts forming the pockets between them. These abutment regions are small and are distributed on said sides, and do not always conform closely to the ellipsoidal surface of an egg, thus creating a risk of breakage due to individual abutment regions, especially at their edges, being pressed into the eggshell, the latter being unable to resist such a concentrated load. This problem is not made less serious by the fact that a new size classification for eggs has been introduced. According to this new classification, an egg tray of a given size is expected to accommodate eggs within a size interval that is greater than was the case with the previous classification. When using the previously known egg trays, this may result in that many eggs, especially the smallest ones within the class concerned, will not come to rest steadily in the egg-supporting surface or other surfaces. This risk of instability is particularly important when at the production site manually or mechanically placing the eggs in the egg trays, as it is important, not only with regard to placing another egg tray on top of one having just been filled, that the eggs having been deposited in the pockets automatically assume a steady and predictable orientation, but also with regard to the mechanized packaging subsequently taking place at the packaging station, in which the eggs are lifted from the trays by means of suction cups as described in the preceding paragraph.
Various attempts have been made to solve these problems, such as by increasing the size of the various abutment regions, but these attempts have only met with limited success, presumably because the number of abutment regions, and in particular the number of edges, has not been appreciably reduced, so that the risk of breakage or instability has not been reduced to any considerable extent.
It is the object of the present invention to provide an egg tray of the kind referred to initially, with which the disadvantages referred to above are considerably reduced, and this object is achieved with an egg tray of said kind, comprising only one single abutment region constituted by the continuous ellipsoidal or quasi-ellipsoidal surface, on which the eggs when deposited will come to rest in stable and predictable orientations, with their weight more or less evenly distributed over the entire surface, thus avoiding both local stress concentrations and instability, as well as ensuring a good engagement with the suction cups used to remove the eggs from the trays.
Other advantageous features of the egg tray acccording to the invention are also described.